Inositol phosphates in receptor-mediated cell signaling: metabolic origins and interrelationships.
We have investigated the metabolic interrelationships of the major inositol phosphates in vasopressin-stimulated WRK 1 mammary tumor cells which were labeled to equilibrium with [14C]inositol and briefly, just prior to stimulation, with [3H]inositol. A comparison of the 3H/14C ratios of these compounds with those of the cellular inositol lipids suggests that most of the known inositol mono-, bis-, tris-, and tetrakis-phosphates are derived from precursors with turnover rates similar to those of these lipids. However, Ins(3,4,5,6)P4 (which is the major inositol tetrakisphosphate to accumulate in stimulated WRK 1 cells), Ins(1,3,4,5,6)P5, and InsP6 had 3H/14C ratios of 0 in this experiment, indicating that they must have a different metabolic origin.
Kirk
C J
CJ
School of Biochemistry, University of Birmingham, United Kingdom.
Maccallum
S H
SH
Michell
R H
RH
Barker
C J
CJ
D000818:Animals; D002450:Cell Communication / Q000502:physiology*; D007295:Inositol Phosphates / Q000502:physiology*; D008325:Mammary Neoplasms, Experimental / Q000378:metabolism; D051381:Rats; D015398:Signal Transduction / Q000502:physiology*; D014407:Tumor Cells, Cultured
D007295:Inositol Phosphates